1. Field of the Invention
This invention relates to a method and apparatus for the spectrographic analysis of workpieces formed from iron and/or steel alloys, and more particularly to a method and apparatus wherein a test head of a spectrometer is attached to a workpiece to be analyzed whereupon a unipolar discharge is triggered between the counterelectrode of the test head and the workpiece. Light generated from the discharge is imaged onto a grating of the spectrometer.
2. Description of the Prior Art
Spectrometers have long been known in the iron and steel producing industry. As a rule, stationary laboratory instruments have been employed which have the drawback that material samples have to be separated from the workpiece to be analyzed and placed in the spectrometer in the laboratory. Efforts have also been made to determine the alloy constituents of workpieces without separating the material samples from the workpieces by using transportable spectrometers available on the market which utilize a transportable test head.
However, whereas the carbon constituent of iron or steel alloys can readily be analyzed with the stationary units noted above, it has been found that in the case of the prior art transportable units no interpretable effects have been produced. In addition to the C1931.02 carbon line occurring in the stationary units, two additional lines are found that are partly superimposed with the carbon line, so that evaluation of the carbon line is not possible. These are the Fe1931.4 and Fe1930.8 iron lines. Particularly aggravating is the fact that the intensity of these lines is not constant for the same workpiece, which results in failure of the conventional electronic devices. For a long time these effects could not be interpreted. Accordingly, the transportable spectrometer according to the invention was developed to overcome such drawbacks and to allow analysis of workpieces outside of the laboratory. The transportable spectrometer was developed in accordance with the comparative principle set forth in German Pat. Nos. 25 13 266, 25 13 267, and 25 13 279.